Multifrequency Bioelectrical Impedance Analysis Compared With Computed Tomography for Assessment of Skeletal Muscle Mass in Primary Colorectal Malignancy: A Predictor of Short-Term Outcome After Surgery.

Herein, we evaluate the accuracy and reliability of multifrequency bioelectrical impedance analysis (BIA) to assess skeletal muscle mass (SMM) in the colorectal cancer patient compared with computed tomography (CT) scan and also analyze the association between SMM of BIA and postoperative outcomes. From March to May 2017, the body composition of patients scheduled for elective surgery due to primary colorectal cancer in our institution was analyzed at the time of admission using BIA (InBody S20, Biospace Co Ltd, Seoul, South Korea). The relationship between the single cross-sectional area of skeletal muscle at the lumbar region using preoperative CT scan and the SMM determined via BIA were assessed. Postoperative outcomes were compared according to different status of SMM on BIA categorized into 3 groups (low, medium, or high). Fifty patients were analyzed, and the length of hospital stay was shorter and the initiation of oral diet was significantly earlier in the group with high SMM than in other groups (P = 0.001 and 0.038, respectively). The SMM on BIA showed a very significant correlation with skeletal muscle index using CT scan (0.705 of correlation coefficients, P < 0.001) and also strongly correlated with skeletal muscle index after adjusting for age, weight, and BMI on multivariate analysis (β = 0.391 ± 0.057, P < 0.001). SMM determined by BIA is strongly correlated with SMM estimated by CT scan. Authors suppose that BIA could be an alternative to CT scan for the assessment of SMM in colorectal cancer patients.

Kim EY ，Kim SR ，Won DD ，Choi MH ，Lee IK ... -  《-》

Comparative assessment of skeletal muscle mass using computerized tomography and bioelectrical impedance analysis in critically ill patients.

We compared the evaluation of skeletal muscle mass (SMM) using the computed tomography (CT) and bioelectrical impedance analysis (BIA) methods in critically ill patients. We also evaluated whether BIA can be applied for measuring SM with high accuracy to critically ill patients. We included 135 critically ill surgical patients (83 men and 52 women, mean age: 59.3 years) who got the BIA and abdominal CT scan both within 7 days during the intensive care unit (ICU) stay. With CT scan, skeletal muscle area (SMA) measured from the L3 spine level image was used for calculation of the whole body skeletal muscle volume and mass (kg). Body composition data from BIA were obtained using touch-type electrodes and 50 kHz current. Subgroup analyses for SMM were performed according to the sex, SMA, and edema status of the patients with Pearson correlation or regression analysis et al. SMM from CT and BIA showed a good correlation (p < 0.0001) to sex, SMA, and edema in the subgroup analysis. A stronger correlation was noted between SMM from CT and BIA in male patients or mild edema group than for the other groups. SMM from BIA showed greater values than that from CT (mean difference, 3.35 kg) in all groups, except the normal SMA (higher than 170 cm2 in men, and 110 cm2 in women) group. Male patients and mild edema group showed more SMM as evaluated by BIA when compared to the other groups. SMM measure by BIA in critically ill patients showed high correlation with SMM calculation by CT scan and had greater values than SMM from CT scan. Ajou University Hospital Institutional Review Board DEV-DE4-15-115, Registered Jan 1 2015.

Kim D ，Sun JS ，Lee YH ，Lee JH ，Hong J ，Lee JM ... -  《-》

Correlation Between Bioelectrical Impedance Analysis and Chest CT-Measured Erector Spinae Muscle Area: A Cross-Sectional Study.

Skeletal muscle mass (SMM) plays an important part in diverse health and disease states. Bioelectrical impedance analysis (BIA) and computed tomography (CT) are available for its assessment. However, muscle mass assessed by BIA may be influenced by multiple factors. The erector spinae muscle area (ESA) on chest CT is recently presumed to be representative of SMM. This study aimed to derive BIA from the ESA and evaluate the magnitude of association (between ESA measured from chest CT) and BIA. Subjects hospitalized for health checkups between December 2020 and December 2021, having undergone both BIA (50 kHz, 0.8 mA) and chest CT, were included. ESA was quantified at the level of the 12th thoracic vertebra (T12-ESA) by a standardized semi-automated segmentation algorithm. Low SMM was defined using the Asian Working Group for Sarcopenia criteria. The association between T12-ESA and BIA was then evaluated. Stratified analyses by sex and BMI were also performed. Among 606 included subjects (59.7 ± 16.6 years, 63.5% male), 110 (18.2%) had low SMM. BMI in low and normal SMM groups was 20.1 and 24.7 kg/m2, respectively. Current smoking, drinking, chronic obstructive pulmonary disease, and chronic renal dysfunction were more frequently seen in the low SMM group than in the normal SMM group. The final regression model included T12-ESA, weight, BMI, and age, and had an adjusted R2 of 0.806 with BIA. In the validation group, the correlation between T12-ESA-derived BIA and BIA remained high (Pearson correlation = 0.899). Stratified analysis disclosed a stronger correlation between T12-ESA and BIA in male subjects than in female subjects (adjusted R2 = 0.790 vs. adjusted R2 = 0.711, p < 0.05), and a better correlation was observed in obese (BMI ≥ 30 kg/m2) compared with underweight (BMI < 18.5 kg/m2) subjects (adjusted R2 = 0.852 vs. adjusted R2 = 0.723, p < 0.05). Additional analysis revealed a significant correlation between T12-ESA and skeletal muscle cross-sectional area at the 3rd lumbar vertebra (L3-CSA) (adjusted R2 = 0.935, p < 0.001). CT-based assessment of ESA at the T12 level is feasible and correlated well with BIA, especially in male subjects and obese subjects.

Cao J ，Zuo D ，Han T ，Liu H ，Liu W ，Zhang J ，Weng Y ，Jin X ，Chen Z ，Hu Y ... -  《Frontiers in Endocrinology》

Identifying critically ill patients with low muscle mass: Agreement between bioelectrical impedance analysis and computed tomography.

Low muscle mass and -quality on ICU admission, as assessed by muscle area and -density on CT-scanning at lumbar level 3 (L3), are associated with increased mortality. However, CT-scan analysis is not feasible for standard care. Bioelectrical impedance analysis (BIA) assesses body composition by incorporating the raw measurements resistance, reactance, and phase angle in equations. Our purpose was to compare BIA- and CT-derived muscle mass, to determine whether BIA identified the patients with low skeletal muscle area on CT-scan, and to determine the relation between raw BIA and raw CT measurements. This prospective observational study included adult intensive care patients with an abdominal CT-scan. CT-scans were analysed at L3 level for skeletal muscle area (cm2) and skeletal muscle density (Hounsfield Units). Muscle area was converted to muscle mass (kg) using the Shen equation (MMCT). BIA was performed within 72 h of the CT-scan. BIA-derived muscle mass was calculated by three equations: Talluri (MMTalluri), Janssen (MMJanssen), and Kyle (MMKyle). To compare BIA- and CT-derived muscle mass correlations, bias, and limits of agreement were calculated. To test whether BIA identifies low skeletal muscle area on CT-scan, ROC-curves were constructed. Furthermore, raw BIA and CT measurements, were correlated and raw CT-measurements were compared between groups with normal and low phase angle. 110 patients were included. Mean age 59 ± 17 years, mean APACHE II score 17 (11-25); 68% male. MMTalluri and MMJanssen were significantly higher (36.0 ± 9.9 kg and 31.5 ± 7.8 kg, respectively) and MMKyle significantly lower (25.2 ± 5.6 kg) than MMCT (29.2 ± 6.7 kg). For all BIA-derived muscle mass equations, a proportional bias was apparent with increasing disagreement at higher muscle mass. MMTalluri correlated strongest with CT-derived muscle mass (r = 0.834, p < 0.001) and had good discriminative capacity to identify patients with low skeletal muscle area on CT-scan (AUC: 0.919 for males; 0.912 for females). Of the raw measurements, phase angle and skeletal muscle density correlated best (r = 0.701, p < 0.001). CT-derived skeletal muscle area and -density were significantly lower in patients with low compared to normal phase angle. Although correlated, absolute values of BIA- and CT-derived muscle mass disagree, especially in the high muscle mass range. However, BIA and CT identified the same critically ill population with low skeletal muscle area on CT-scan. Furthermore, low phase angle corresponded to low skeletal muscle area and -density. ClinicalTrials.gov (NCT02555670).

Looijaard WGPM ，Stapel SN ，Dekker IM ，Rusticus H ，Remmelzwaal S ，Girbes ARJ ，Weijs PJM ，Oudemans-van Straaten HM ... -  《-》

Accuracy of surrogate methods to estimate skeletal muscle mass in non-dialysis dependent patients with chronic kidney disease and in kidney transplant recipients.

Bioelectrical impedance analysis (BIA) and anthropometric predictive equations have been proposed to estimate whole-body (SMM) and appendicular skeletal muscle mass (ASM) as surrogate for dual energy X-ray absorptiometry (DXA) in distinct population groups. However, their accuracy in estimating body composition in non-dialysis dependent patients with chronic kidney disease (NDD-CKD) and kidney transplant recipients (KTR) is unknown. The aim of this study was to investigate the accuracy and reproducibility of BIA and anthropometric predictive equations in estimating SMM and ASM compared to DXA, in NDD-CKD patients and KTR. A cross-sectional study including adult NDD-CKD patients and KTR, with body mass index (BMI) ≥18.5 kg/m2. ASM and estimated SMM were evaluated by DXA, BIA (Janssen, Kyle and MacDonald equations) and anthropometry (Lee and Baumgartner equations). Low muscle mass (LowMM) was defined according to cutoffs proposed by guidelines for ASM, ASM/height2 and ASM/BMI. The best performing equation as surrogate for DXA, considering both groups of studied patients, was defined based in the highest Lin's concordance correlation coefficient (CCC) value, the lowest Bland-Altman bias (<1.5 kg) combined with the narrowest upper and lower limits of agreement (LoA), and the highest Cohen's kappa values for the low muscle mass diagnosis. Studied groups comprised NDD-CKD patients (n = 321: males = 55.1%; 65.4 ± 13.1 years; eGFR = 28.8 ± 12.7 ml/min) and KTR (n = 200: males = 57.7%; 47.5 ± 11.3 years; eGFR = 54.7 ± 20.7 ml/min). In both groups, the predictive equations presenting the best accuracy compared to DXA were SMM-BIA-Janssen (NDD-CKD patients: CCC = 0.88, 95%CI = 0.83-0.92; bias = 0.0 kg; KTR: CCC = 0.89, 95%CI = 0.86-0.92, bias = -1.2 kg) and ASM-BIA-Kyle (NDD-CKD patients: CCC = 0.87, 95%CI = 0.82-0.90, bias = 0.7 kg; KTR: CCC = 0.89, 95%CI = 0.86-0.92, bias = -0.8 kg). In NDD-CKD patients and KTR, LowMM frequency was similar according to ASM-BIA-Kyle versus ASM-DXA. The reproducibility and inter-agreement to diagnose LowMM using ASM/height2 and ASM/BMI estimated by BIA-Kyle equation versus DXA was moderate (kappa: 0.41-0.60), in both groups. Whereas female patients showed higher inter-agreement (AUC>80%) when ASM/BMI index was used, male patients presented higher AUC (70-74%; slightly <80%) for ASM/height2 index. The predictive equations with best performance to assess muscle mass in both NDD-CKD patients and KTR was SMM-BIA by Janssen and ASM-BIA by Kyle. The reproducibility to diagnose low muscle mass, comparing BIA with DXA, was high using ASM/BMI in females and ASM/height2 in males in both groups.

Barreto Silva MI ，Menna Barreto APM ，Pontes KSDS ，Costa MSD ，Rosina KTC ，Souza E ，Bregman R ，Prado CM ，Klein MRST ... -  《-》